/* -*- C++ -*-

 *

 * This file is a part of LEMON, a generic C++ optimization library

 *

 * Copyright (C) 2003-2007

 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

 * (Egervary Research Group on Combinatorial Optimization, EGRES).

 *

 * Permission to use, modify and distribute this software is granted

 * provided that this copyright notice appears in all copies. For

 * precise terms see the accompanying LICENSE file.

 *

 * This software is provided "AS IS" with no warranty of any kind,

 * express or implied, and with no claim as to its suitability for any

 * purpose.

 *

 */

///\file

///\brief Implementation of the LEMON-GLPK mip solver interface.

#include <lemon/mip_glpk.h>

namespace lemon {

  MipGlpk::MipGlpk() {

    lpx_set_class(lp,LPX_MIP);

  }

  void MipGlpk::_colType(int i, MipGlpk::ColTypes col_type){

    switch (col_type){

      case INT:

	lpx_set_col_kind(lp,i,LPX_IV);

	break;

      case REAL:

	lpx_set_col_kind(lp,i,LPX_CV);

	break;

    default:;

        //FIXME problem

    }

  }

  MipGlpk::ColTypes MipGlpk::_colType(int i) const {

    switch (lpx_get_col_kind(lp,i)){

    case LPX_IV:

      return INT;//Or binary

    case LPX_CV:

      return REAL;

    default:

      return REAL;//Error!

    }

  }

  LpGlpk::SolveExitStatus MipGlpk::_solve() {

    int result = lpx_simplex(lp);

    //

    if (lpx_get_status(lp)==LPX_OPT){

      //Maybe we could try the routine lpx_intopt(lp), a revised

      //version of lpx_integer

      result = lpx_integer(lp);

      switch (result){

      case LPX_E_OK:

	return SOLVED;

      default:

	return UNSOLVED;

      }

    }

    return UNSOLVED;

  }

  LpGlpk::SolutionStatus MipGlpk::_getMipStatus() const {

    if (lpx_get_status(lp)==LPX_OPT){

      //Meg kell nezni: ha az LP is infinite, akkor ez is, ha az is

      //infeasible, akkor ez is, de ez lehet maskepp is infeasible.

      int stat=  lpx_mip_status(lp);

      switch (stat) {

      case LPX_I_UNDEF://Undefined (no solve has been run yet)

	return UNDEFINED;

      case LPX_I_NOFEAS://There is no feasible integral solution

	return INFEASIBLE;

	//     case LPX_UNBND://Unbounded

	//       return INFINITE;

      case LPX_I_FEAS://Feasible

	return FEASIBLE;

      case LPX_I_OPT://Feasible

	return OPTIMAL;

      default:

      return UNDEFINED; //to avoid gcc warning

      //FIXME error

      }

    }

    else 

      return UNDEFINED; //Maybe we could refine this: what does the LP

			//relaxation look like

  }  

  MipGlpk::Value MipGlpk::_getPrimal(int i) const {

    return lpx_mip_col_val(lp,i);

  }

  MipGlpk::Value MipGlpk::_getPrimalValue() const {

    return lpx_mip_obj_val(lp);

  }

} //END OF NAMESPACE LEMON